Initializing terminals in a signal distribution system
First Claim
1. In a signal distribution system having a system having a server and a plurality of terminals, each said terminal having a specified address for responding to polls and receiving control messages and wherein each said terminal responds to each poll addressed thereto with an uplink message to said server, a method of remotely assigning said specified addresses to newly-connected terminals, which comprises:
- in said server;
storing said specified address in a polling list and repeatedly polling said terminals in accordance with said polling list; and
periodically broadcasting a control message containing a tentative address to all said terminals followed by polling said tentative address;
in a newly-connected terminal;
receiving one of said broadcast control messages, storing the tentative address contained in said broadcast control message as the specified address for said terminal and, in response to a poll to said tentative address, sending an initial uplink message to said server;
in said server;
in response to said initial uplink message, inserting said tentative address in said polling list as the specified address for said newly-connected terminal, selecting a new tentative address for use in subsequent broadcast control messages, periodically polling said specified address, receiving additional uplink messages from said newly-connected terminal and echoing at least one of said uplink messages in at least one additional control message addressed to said specified address,in said newly-connected terminal;
comparing at least one character from said echoed uplink messages in said additional control messages with the corresponding at least one character in the uplink messages sent and, if said comparison reveals a difference, repeating said receiving step to acquire a different tentative address for use as the specified address of said terminal.
1 Assignment
0 Petitions
Accused Products
Abstract
Signal distribution systems, such as interactive cable television systems, have a central server that communicates with remote terminals wherein the server assigns a specific address to each newly-connected terminal for control messages and polls. In the case of an interactive cable television system, such terminal is the set-top box or converter connected between the cable system and the television receiver. Periodically, the server broadcasts a control message containing a tentative address, and polls the tentative address. Upon receiving such a message, a newly-connected converter stores the tentative address and responds to the poll with an uplink message. After receiving the uplink message, the server inserts the tentative address in its polling list in accordance with the transmission delay measured from sending the poll to receiving the uplink message and selects a new tentative address to use in subsequent broadcast control messages. Uplink messages are echoed by the server and verified by the converter. If the converter cannot verify an echoed uplink message, which can occur if more than one newly-connected converter responds to the same broadcast control message, the converter repeats its initialization procedure to acquire a new address. After the initialization is complete, system software can be downloaded from the server to the converter and the converter placed in service.
134 Citations
9 Claims
-
1. In a signal distribution system having a system having a server and a plurality of terminals, each said terminal having a specified address for responding to polls and receiving control messages and wherein each said terminal responds to each poll addressed thereto with an uplink message to said server, a method of remotely assigning said specified addresses to newly-connected terminals, which comprises:
-
in said server; storing said specified address in a polling list and repeatedly polling said terminals in accordance with said polling list; and periodically broadcasting a control message containing a tentative address to all said terminals followed by polling said tentative address; in a newly-connected terminal; receiving one of said broadcast control messages, storing the tentative address contained in said broadcast control message as the specified address for said terminal and, in response to a poll to said tentative address, sending an initial uplink message to said server; in said server; in response to said initial uplink message, inserting said tentative address in said polling list as the specified address for said newly-connected terminal, selecting a new tentative address for use in subsequent broadcast control messages, periodically polling said specified address, receiving additional uplink messages from said newly-connected terminal and echoing at least one of said uplink messages in at least one additional control message addressed to said specified address, in said newly-connected terminal; comparing at least one character from said echoed uplink messages in said additional control messages with the corresponding at least one character in the uplink messages sent and, if said comparison reveals a difference, repeating said receiving step to acquire a different tentative address for use as the specified address of said terminal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. In a signal distribution system having a server and a plurality of terminals, each said terminal having a specified address for responding to polls and receiving control messages from said server and wherein each said terminal responds to each poll addressed thereto with an uplink message to said server, a method of remotely assigning said specified addresses to newly-connected terminals, which comprises:
-
repeatedly polling said specified addresses, periodically sending a tentative address from said server to all said terminals and polling said tentative address, in a newly-connected terminal, receiving and storing said tentative address as the specified address for said terminal and sending an initial uplink message in response to said tentative- address poll, in said server, on receipt of said uplink message, including said tentative address as a specified address, choosing a new tentative address and echoing at least one uplink message to said newly- connected terminal, in said newly-connected terminal, comparing at least one echoed uplink message with the uplink message as sent, and if such messages are different, repeating said receiving and storing step to acquire a different specified address.
-
Specification